1. Field of the Invention
The invention relates to a system for displaying images, and more particularly to a touch sensing circuit of a system for displaying images.
2. Description of the Related Art
Currently, due to integrated information application products, touch panels have gradually replaced conventional human-machine interfaces, such as keyboards and mice. Since users can operate touch panels easily and conveniently, touch panels have been applied in many fields; for example, portable communication products and information products, bank/commerce systems, medicine registering systems, factory monitor systems, public information guiding systems, etc. According to sensing methods, touch panels are divided into a capacitance type, a resistance type, a sound-wave type, an infrared-ray type, and a magnetism-sensing type. The capacitance type is usually applied in large-sized touch panels. Touch between a finger/touch stylus and a touch panel causes a capacitance change and further generates a corresponding voltage. According to the generated voltage, the position of the touch point is detected in X and Y directions, and signals or instructions corresponding to the touch point is sent.